Assurnasirpal II (883-859 BC) moved the Assyrian court away from Assur to Kalhu, and this city subsequently served as Assyria's administrative centre and the king's main residence until Sargon II (721-705 BC) built the new city of Dur-Šarruken to fulfil these functions.

In the first millennium BC, Kalhu (modern Nimrud) was one of the most important cities of the Assyrian Empire. But the site was already inhabited in the 6th millennium BC and, from at least the early second millennium BC, was one of the foremost north Mesopotamian centres, then known under the name Kawalhum or Kawilhum. In the later second millennium BC, Kalhu was the capital of a province of the Middle Assyrian kingdom - a status which the city held until the collapse of the Assyrian Empire at the end of the 7th century BC.

Subsequently, the site was not completely abandoned but, while there is evidence for its continued habitation until the Hellenistic period, Kalhu was no longer an important city: when Xenophon and his Greek mercenaries passed by the site, then known as Larissa, at the close of the 5th century BC, it lay in ruins and was inhabited only by squatters who had taken refuge in the remains of what must be the ziggurat of the Ninurta temple.

Kalhu is situated in the centre of a triangle formed by the three most important cities of central Assyria: Assur in the south, Nineveh in the north and Arbela in the east. The city lies on the eastern bank of the Tigris, near the convergence with the Greater Zab, and held an important position in the long distance traffic network, both over land and on the rivers. Not only was it an important stop on the north-south route along the Tigris, it also controlled a key route leading east via Arbela towards the Zagros Mountains and, along their western fringes, south into Babylonia.

Until the reign of Assurnasirpal II, the religious and ideological centre of Assyria, the city of Assur, served also as the king's main residence. Assurnasirpal, however, relocated the entire royal court, moving hundreds of people under the supervision of his palace superintendent Nergal-apil-kumuya to Kalhu after this ancient city had been completely transformed. The old settlement mound, having grown to a substantial height in the course of its five thousand year long occupation, was turned into a citadel that housed only the royal palace and several temples of the most important deities of Assyria, such as Ninurta and Ištar - but not a shrine for Aššur, whose only sanctuary remained in the city of Assur. The citadel was protected by its own fortification walls but occupied only a small part in the south-western corner of the larger city: with a size of about 360 hectares, Assurnasirpal's Kalhu covered twice the area of Assur and was surrounded by a 7.5 km long fortification wall.

We do not know why Assurnasirpal moved the court away from Assur.

Whatever the reason, Kalhu's most impressive building at the time of Assurnasirpal was certainly his new royal palace. At 200 metres long and 130 metres wide, it dominated its surroundings and its position on the citadel mound led to its modern name, the Northwest Palace. It was organised around three courtyards, accommodating the state apartments, the administrative wing and the private quarters which also housed the royal women. Here, several underground tombs were uncovered in 1989, including the last resting place of Assurnasirpal's queen Mullissu-mukannišat-Ninua, the daughter of the king's cupbearer, one of the foremost officials at court. Her rich burial goods give a vivid impression of the luxury in which the king and his entourage lived.

Kalhu served as the main residence of all Assyrian kings up to Tiglath-pileser III (744-727 BC) but, while Assurnasirpal's palace was not abandoned, several of his successors built their own palaces in Kalhu, among them Adad-nerari III (810-783 BC), whose palace was excavated by an Iraqi team in 1993, and also Tiglath-pileser.

The stone parts of their buildings as well as of the Northwest Palace were later ransacked to provide building materials for a palace of Esarhaddon's which remained unfinished but holds an important position in the history of Near Eastern architecture as a result of its columned halls.

Tiglath-pileser's palace is known today as the Central Palace but its ancient name was "Palaces of joy which bear abundance (and) bless the king who made their structure everlasting" (Tiglath-pileser III 47, rev. 34'). The ceremonial name given to the palace gateway makes it clear that the king saw Kalhu not just as the centre of Assyria but of the entire world: "Gates of justice which pass fair judgement on the rulers of the four corners (of the world), which offer the tribute from the mountains and the sea, which admit the produce of mankind before the king, their lord" (Tiglath-pileser III 47, rev. 35'-36').

Nimrud (Arabic: كال‎) is the later Arab name for the ancient Assyrian city of Kalhu located south of Mosul on the river Tigris in northern Mesopotamia. Archeologists called the city Nimrud after the Biblical Nimrod, a legendary hunting hero (cf. Genesis 10:11-12, Micah 5:5, and 1Chronicles 1:10). The city was known as Calah (Kalakh) in the Bible.

The city covered an area of 360 hectares. The ruins of the city are found within one kilometer of the modern-day Assyrian village of Noomanea in Nineveh Province, Iraq. This is some 30 kilometressoutheast of Mosul.

Artemisia herba-alba is thought to be a plant translated as "wormwood" in English language versions of the Bible ("apsinthos" in the Greek text). Wormwood is mentioned seven times in the Jewish Bible, always with the implication of bitterness.

Although the word wormwood appears several times in the Old Testament, translated from the Hebrew term לענה (la'anah) (which means "curse" in Arabic and Hebrew), its only clear reference as a named entity occurs in the New Testament, in the Book of Revelation: "The third angel sounded his trumpet, and a great star, blazing like a torch, fell from the sky on a third of the rivers and on the springs of water— the name of the star is Wormwood. A third of the waters turned bitter, and many people died from the waters that had become bitter." (Rev 8:10–11)

---Artemisia herba-alba is thought to be the plant translated as "wormwood" in English language versions of the Bible ("apsinthos" in the Greek text). Wormwood is mentioned seven times in the Jewish Bible, always with the implication of bitterness. Wormwood is mentioned once in the New Testament, as the name of a star, also with implications of bitterness.